Numerous pharmaceutical agents are applied as solutions but are unstable in the dissolved state. However, the pharmaceutical agents as freeze-dried formulations can be stored in a stable manner and be dissolved again immediately prior to being used. Examples thereof to be mentioned are biotechnological products, peptides, vaccines, and certain reagents.
More recently, such formulations are also produced in the form of more or less spherical multi-particular preparations as so-called cryo-pellets. To this end, the source solution is brought into a drop form, wherein drops having an accurately defined volume are producible. These drops are frozen, for example in liquid nitrogen, and are then dried by way of sublimation. The dry cryo-pellets that are produced in this way have at least approximately a spherical configuration having a defined mean diameter. If required, the cryo-pellets can again be dissolved in suitable quantities. The target herein is to produce only such a limited quantity of solution as is required for covering the immediate demand, to which end corresponding quantities of cryo-pellets are kept available in suitable packaging units.
The number of cryo-pellets required for preparing a solution is typically very low. Consequently, only a single pellet or just a few pellets are required which is why a volumetric metering in the filling of respective packaging units is precluded. Rather, a filling of the packaging units with a specific suitable number of pellets is targeted, to which end the pellets in this very number have to be separated from a comparatively large supply and then have to be transferred into the target container. However, the prior art does not provide any suitable method for separating and for transferring and also no device suitable for this purpose, which can be traced back to inter alia the following aspects:                Cryo-pellets are extremely fragile and sensitive to abrasion. Existing supply technologies (for example slides, vibration infeeds) lead to mechanical damage to the pellets.        The density of the pellets, being ρ<0.2 g/ml, is so minor that the weight of the pellets alone is hardly sufficient for a targeted supply.        The pellets in the case of frequent contact with one another and with other surfaces have a pronounced tendency toward electrostatic charging, this being critical in particular in the case of a vibration infeed.        Filling has in most cases to be performed at very low relative humidity or under a protective gas atmosphere.        